High-energy radiation has been used in many industrial and scientific applications. However, it usually has a negative impact on human health. Special attention has been paid to visualization and monitoring of harmful radiation to quantify the radiation intensity and prevent the undesired exposition. Radioluminescence optical fibers represent a special category of components allowing the construction of distributed radioluminescence sensors. We successfully implemented Eu-doped ZnO nanoparticles into optical fiber to prepare radioluminescence optical fiber. The concentration of ZnO was 0.85 at.% and the refractive index of the core was 1.459. The background optical losses reached the values of 10.74, 1.87, and 0.83 dBm-1 recorded at 450, 550 and 850 nm, respectively. We proved that the fiber exhibits luminescence properties under UV excitation showing broad luminescence band in the 350 to 550 nm range and two well pronounced luminescence bands of Eu3+ ions in the 560 and 640 nm range. Fiber can be used as a sensing element in distributed radioluminescence sensors for monitoring of high-energy radiation.